gh-108303: Move `test_future` into its own test_future_stmt subdir (#109368)

1 files changed, 460 insertions, 0 deletions

diff --git a/Lib/test/test_future_stmt/test_future.py b/Lib/test/test_future_stmt/test_future.py
new file mode 100644
index 0000000..8e67bcd
--- /dev/null
+++ b/Lib/test/test_future_stmt/test_future.py
@@ -0,0 +1,460 @@
+# Test various flavors of legal and illegal future statements
+
+import __future__
+import ast
+import unittest
+from test.support import import_helper
+from test.support.script_helper import spawn_python, kill_python
+from textwrap import dedent
+import os
+import re
+import sys
+
+rx = re.compile(r'\((\S+).py, line (\d+)')
+
+def get_error_location(msg):
+    mo = rx.search(str(msg))
+    return mo.group(1, 2)
+
+class FutureTest(unittest.TestCase):
+
+    def check_syntax_error(self, err, basename, lineno, offset=1):
+        self.assertIn('%s.py, line %d' % (basename, lineno), str(err))
+        self.assertEqual(os.path.basename(err.filename), basename + '.py')
+        self.assertEqual(err.lineno, lineno)
+        self.assertEqual(err.offset, offset)
+
+    def test_future1(self):
+        with import_helper.CleanImport('test.test_future_stmt.future_test1'):
+            from test.test_future_stmt import future_test1
+            self.assertEqual(future_test1.result, 6)
+
+    def test_future2(self):
+        with import_helper.CleanImport('test.test_future_stmt.future_test2'):
+            from test.test_future_stmt import future_test2
+            self.assertEqual(future_test2.result, 6)
+
+    def test_future_single_import(self):
+        with import_helper.CleanImport(
+            'test.test_future_stmt.test_future_single_import',
+        ):
+            from test.test_future_stmt import test_future_single_import
+
+    def test_future_multiple_imports(self):
+        with import_helper.CleanImport(
+            'test.test_future_stmt.test_future_multiple_imports',
+        ):
+            from test.test_future_stmt import test_future_multiple_imports
+
+    def test_future_multiple_features(self):
+        with import_helper.CleanImport(
+            "test.test_future_stmt.test_future_multiple_features",
+        ):
+            from test.test_future_stmt import test_future_multiple_features
+
+    def test_badfuture3(self):
+        with self.assertRaises(SyntaxError) as cm:
+            from test.test_future_stmt import badsyntax_future3
+        self.check_syntax_error(cm.exception, "badsyntax_future3", 3)
+
+    def test_badfuture4(self):
+        with self.assertRaises(SyntaxError) as cm:
+            from test.test_future_stmt import badsyntax_future4
+        self.check_syntax_error(cm.exception, "badsyntax_future4", 3)
+
+    def test_badfuture5(self):
+        with self.assertRaises(SyntaxError) as cm:
+            from test.test_future_stmt import badsyntax_future5
+        self.check_syntax_error(cm.exception, "badsyntax_future5", 4)
+
+    def test_badfuture6(self):
+        with self.assertRaises(SyntaxError) as cm:
+            from test.test_future_stmt import badsyntax_future6
+        self.check_syntax_error(cm.exception, "badsyntax_future6", 3)
+
+    def test_badfuture7(self):
+        with self.assertRaises(SyntaxError) as cm:
+            from test.test_future_stmt import badsyntax_future7
+        self.check_syntax_error(cm.exception, "badsyntax_future7", 3, 54)
+
+    def test_badfuture8(self):
+        with self.assertRaises(SyntaxError) as cm:
+            from test.test_future_stmt import badsyntax_future8
+        self.check_syntax_error(cm.exception, "badsyntax_future8", 3)
+
+    def test_badfuture9(self):
+        with self.assertRaises(SyntaxError) as cm:
+            from test.test_future_stmt import badsyntax_future9
+        self.check_syntax_error(cm.exception, "badsyntax_future9", 3)
+
+    def test_badfuture10(self):
+        with self.assertRaises(SyntaxError) as cm:
+            from test.test_future_stmt import badsyntax_future10
+        self.check_syntax_error(cm.exception, "badsyntax_future10", 3)
+
+    def test_ensure_flags_dont_clash(self):
+        # bpo-39562: test that future flags and compiler flags doesn't clash
+
+        # obtain future flags (CO_FUTURE_***) from the __future__ module
+        flags = {
+            f"CO_FUTURE_{future.upper()}": getattr(__future__, future).compiler_flag
+            for future in __future__.all_feature_names
+        }
+        # obtain some of the exported compiler flags (PyCF_***) from the ast module
+        flags |= {
+            flag: getattr(ast, flag)
+            for flag in dir(ast) if flag.startswith("PyCF_")
+        }
+        self.assertCountEqual(set(flags.values()), flags.values())
+
+    def test_parserhack(self):
+        # test that the parser.c::future_hack function works as expected
+        # Note: although this test must pass, it's not testing the original
+        #       bug as of 2.6 since the with statement is not optional and
+        #       the parser hack disabled. If a new keyword is introduced in
+        #       2.6, change this to refer to the new future import.
+        try:
+            exec("from __future__ import print_function; print 0")
+        except SyntaxError:
+            pass
+        else:
+            self.fail("syntax error didn't occur")
+
+        try:
+            exec("from __future__ import (print_function); print 0")
+        except SyntaxError:
+            pass
+        else:
+            self.fail("syntax error didn't occur")
+
+    def test_unicode_literals_exec(self):
+        scope = {}
+        exec("from __future__ import unicode_literals; x = ''", {}, scope)
+        self.assertIsInstance(scope["x"], str)
+
+    def test_syntactical_future_repl(self):
+        p = spawn_python('-i')
+        p.stdin.write(b"from __future__ import barry_as_FLUFL\n")
+        p.stdin.write(b"2 <> 3\n")
+        out = kill_python(p)
+        self.assertNotIn(b'SyntaxError: invalid syntax', out)
+
+class AnnotationsFutureTestCase(unittest.TestCase):
+    template = dedent(
+        """
+        from __future__ import annotations
+        def f() -> {ann}:
+            ...
+        def g(arg: {ann}) -> None:
+            ...
+        async def f2() -> {ann}:
+            ...
+        async def g2(arg: {ann}) -> None:
+            ...
+        class H:
+            var: {ann}
+            object.attr: {ann}
+        var: {ann}
+        var2: {ann} = None
+        object.attr: {ann}
+        """
+    )
+
+    def getActual(self, annotation):
+        scope = {}
+        exec(self.template.format(ann=annotation), {}, scope)
+        func_ret_ann = scope['f'].__annotations__['return']
+        func_arg_ann = scope['g'].__annotations__['arg']
+        async_func_ret_ann = scope['f2'].__annotations__['return']
+        async_func_arg_ann = scope['g2'].__annotations__['arg']
+        var_ann1 = scope['__annotations__']['var']
+        var_ann2 = scope['__annotations__']['var2']
+        self.assertEqual(func_ret_ann, func_arg_ann)
+        self.assertEqual(func_ret_ann, async_func_ret_ann)
+        self.assertEqual(func_ret_ann, async_func_arg_ann)
+        self.assertEqual(func_ret_ann, var_ann1)
+        self.assertEqual(func_ret_ann, var_ann2)
+        return func_ret_ann
+
+    def assertAnnotationEqual(
+        self, annotation, expected=None, drop_parens=False, is_tuple=False,
+    ):
+        actual = self.getActual(annotation)
+        if expected is None:
+            expected = annotation if not is_tuple else annotation[1:-1]
+        if drop_parens:
+            self.assertNotEqual(actual, expected)
+            actual = actual.replace("(", "").replace(")", "")
+
+        self.assertEqual(actual, expected)
+
+    def _exec_future(self, code):
+        scope = {}
+        exec(
+            "from __future__ import annotations\n"
+            + code, scope
+        )
+        return scope
+
+    def test_annotations(self):
+        eq = self.assertAnnotationEqual
+        eq('...')
+        eq("'some_string'")
+        eq("u'some_string'")
+        eq("b'\\xa3'")
+        eq('Name')
+        eq('None')
+        eq('True')
+        eq('False')
+        eq('1')
+        eq('1.0')
+        eq('1j')
+        eq('True or False')
+        eq('True or False or None')
+        eq('True and False')
+        eq('True and False and None')
+        eq('Name1 and Name2 or Name3')
+        eq('Name1 and (Name2 or Name3)')
+        eq('Name1 or Name2 and Name3')
+        eq('(Name1 or Name2) and Name3')
+        eq('Name1 and Name2 or Name3 and Name4')
+        eq('Name1 or Name2 and Name3 or Name4')
+        eq('a + b + (c + d)')
+        eq('a * b * (c * d)')
+        eq('(a ** b) ** c ** d')
+        eq('v1 << 2')
+        eq('1 >> v2')
+        eq('1 % finished')
+        eq('1 + v2 - v3 * 4 ^ 5 ** v6 / 7 // 8')
+        eq('not great')
+        eq('not not great')
+        eq('~great')
+        eq('+value')
+        eq('++value')
+        eq('-1')
+        eq('~int and not v1 ^ 123 + v2 | True')
+        eq('a + (not b)')
+        eq('lambda: None')
+        eq('lambda arg: None')
+        eq('lambda a=True: a')
+        eq('lambda a, b, c=True: a')
+        eq("lambda a, b, c=True, *, d=1 << v2, e='str': a")
+        eq("lambda a, b, c=True, *vararg, d, e='str', **kwargs: a + b")
+        eq("lambda a, /, b, c=True, *vararg, d, e='str', **kwargs: a + b")
+        eq('lambda x, /: x')
+        eq('lambda x=1, /: x')
+        eq('lambda x, /, y: x + y')
+        eq('lambda x=1, /, y=2: x + y')
+        eq('lambda x, /, y=1: x + y')
+        eq('lambda x, /, y=1, *, z=3: x + y + z')
+        eq('lambda x=1, /, y=2, *, z=3: x + y + z')
+        eq('lambda x=1, /, y=2, *, z: x + y + z')
+        eq('lambda x=1, y=2, z=3, /, w=4, *, l, l2: x + y + z + w + l + l2')
+        eq('lambda x=1, y=2, z=3, /, w=4, *, l, l2, **kwargs: x + y + z + w + l + l2')
+        eq('lambda x, /, y=1, *, z: x + y + z')
+        eq('lambda x: lambda y: x + y')
+        eq('1 if True else 2')
+        eq('str or None if int or True else str or bytes or None')
+        eq('str or None if (1 if True else 2) else str or bytes or None')
+        eq("0 if not x else 1 if x > 0 else -1")
+        eq("(1 if x > 0 else -1) if x else 0")
+        eq("{'2.7': dead, '3.7': long_live or die_hard}")
+        eq("{'2.7': dead, '3.7': long_live or die_hard, **{'3.6': verygood}}")
+        eq("{**a, **b, **c}")
+        eq("{'2.7', '3.6', '3.7', '3.8', '3.9', '4.0' if gilectomy else '3.10'}")
+        eq("{*a, *b, *c}")
+        eq("({'a': 'b'}, True or False, +value, 'string', b'bytes') or None")
+        eq("()")
+        eq("(a,)")
+        eq("(a, b)")
+        eq("(a, b, c)")
+        eq("(*a, *b, *c)")
+        eq("[]")
+        eq("[1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or A, 11 or B, 12 or C]")
+        eq("[*a, *b, *c]")
+        eq("{i for i in (1, 2, 3)}")
+        eq("{i ** 2 for i in (1, 2, 3)}")
+        eq("{i ** 2 for i, _ in ((1, 'a'), (2, 'b'), (3, 'c'))}")
+        eq("{i ** 2 + j for i in (1, 2, 3) for j in (1, 2, 3)}")
+        eq("[i for i in (1, 2, 3)]")
+        eq("[i ** 2 for i in (1, 2, 3)]")
+        eq("[i ** 2 for i, _ in ((1, 'a'), (2, 'b'), (3, 'c'))]")
+        eq("[i ** 2 + j for i in (1, 2, 3) for j in (1, 2, 3)]")
+        eq("(i for i in (1, 2, 3))")
+        eq("(i ** 2 for i in (1, 2, 3))")
+        eq("(i ** 2 for i, _ in ((1, 'a'), (2, 'b'), (3, 'c')))")
+        eq("(i ** 2 + j for i in (1, 2, 3) for j in (1, 2, 3))")
+        eq("{i: 0 for i in (1, 2, 3)}")
+        eq("{i: j for i, j in ((1, 'a'), (2, 'b'), (3, 'c'))}")
+        eq("[(x, y) for x, y in (a, b)]")
+        eq("[(x,) for x, in (a,)]")
+        eq("Python3 > Python2 > COBOL")
+        eq("Life is Life")
+        eq("call()")
+        eq("call(arg)")
+        eq("call(kwarg='hey')")
+        eq("call(arg, kwarg='hey')")
+        eq("call(arg, *args, another, kwarg='hey')")
+        eq("call(arg, another, kwarg='hey', **kwargs, kwarg2='ho')")
+        eq("lukasz.langa.pl")
+        eq("call.me(maybe)")
+        eq("1 .real")
+        eq("1.0.real")
+        eq("....__class__")
+        eq("list[str]")
+        eq("dict[str, int]")
+        eq("set[str,]")
+        eq("tuple[()]")
+        eq("tuple[str, ...]")
+        eq("tuple[str, *types]")
+        eq("tuple[str, int, (str, int)]")
+        eq("tuple[*int, str, str, (str, int)]")
+        eq("tuple[str, int, float, dict[str, int]]")
+        eq("slice[0]")
+        eq("slice[0:1]")
+        eq("slice[0:1:2]")
+        eq("slice[:]")
+        eq("slice[:-1]")
+        eq("slice[1:]")
+        eq("slice[::-1]")
+        eq("slice[:,]")
+        eq("slice[1:2,]")
+        eq("slice[1:2:3,]")
+        eq("slice[1:2, 1]")
+        eq("slice[1:2, 2, 3]")
+        eq("slice[()]")
+        # Note that `slice[*Ts]`, `slice[*Ts,]`, and `slice[(*Ts,)]` all have
+        # the same AST, but only `slice[*Ts,]` passes this test, because that's
+        # what the unparser produces.
+        eq("slice[*Ts,]")
+        eq("slice[1, *Ts]")
+        eq("slice[*Ts, 2]")
+        eq("slice[1, *Ts, 2]")
+        eq("slice[*Ts, *Ts]")
+        eq("slice[1, *Ts, *Ts]")
+        eq("slice[*Ts, 1, *Ts]")
+        eq("slice[*Ts, *Ts, 1]")
+        eq("slice[1, *Ts, *Ts, 2]")
+        eq("slice[1:2, *Ts]")
+        eq("slice[*Ts, 1:2]")
+        eq("slice[1:2, *Ts, 3:4]")
+        eq("slice[a, b:c, d:e:f]")
+        eq("slice[(x for x in a)]")
+        eq('str or None if sys.version_info[0] > (3,) else str or bytes or None')
+        eq("f'f-string without formatted values is just a string'")
+        eq("f'{{NOT a formatted value}}'")
+        eq("f'some f-string with {a} {few():.2f} {formatted.values!r}'")
+        eq('''f"{f'{nested} inner'} outer"''')
+        eq("f'space between opening braces: { {a for a in (1, 2, 3)}}'")
+        eq("f'{(lambda x: x)}'")
+        eq("f'{(None if a else lambda x: x)}'")
+        eq("f'{x}'")
+        eq("f'{x!r}'")
+        eq("f'{x!a}'")
+        eq('[x for x in (a if b else c)]')
+        eq('[x for x in a if (b if c else d)]')
+        eq('f(x for x in a)')
+        eq('f(1, (x for x in a))')
+        eq('f((x for x in a), 2)')
+        eq('(((a)))', 'a')
+        eq('(((a, b)))', '(a, b)')
+        eq("1 + 2 + 3")
+
+    def test_fstring_debug_annotations(self):
+        # f-strings with '=' don't round trip very well, so set the expected
+        # result explicitly.
+        self.assertAnnotationEqual("f'{x=!r}'", expected="f'x={x!r}'")
+        self.assertAnnotationEqual("f'{x=:}'", expected="f'x={x:}'")
+        self.assertAnnotationEqual("f'{x=:.2f}'", expected="f'x={x:.2f}'")
+        self.assertAnnotationEqual("f'{x=!r}'", expected="f'x={x!r}'")
+        self.assertAnnotationEqual("f'{x=!a}'", expected="f'x={x!a}'")
+        self.assertAnnotationEqual("f'{x=!s:*^20}'", expected="f'x={x!s:*^20}'")
+
+    def test_infinity_numbers(self):
+        inf = "1e" + repr(sys.float_info.max_10_exp + 1)
+        infj = f"{inf}j"
+        self.assertAnnotationEqual("1e1000", expected=inf)
+        self.assertAnnotationEqual("1e1000j", expected=infj)
+        self.assertAnnotationEqual("-1e1000", expected=f"-{inf}")
+        self.assertAnnotationEqual("3+1e1000j", expected=f"3 + {infj}")
+        self.assertAnnotationEqual("(1e1000, 1e1000j)", expected=f"({inf}, {infj})")
+        self.assertAnnotationEqual("'inf'")
+        self.assertAnnotationEqual("('inf', 1e1000, 'infxxx', 1e1000j)", expected=f"('inf', {inf}, 'infxxx', {infj})")
+        self.assertAnnotationEqual("(1e1000, (1e1000j,))", expected=f"({inf}, ({infj},))")
+
+    def test_annotation_with_complex_target(self):
+        with self.assertRaises(SyntaxError):
+            exec(
+                "from __future__ import annotations\n"
+                "object.__debug__: int"
+            )
+
+    def test_annotations_symbol_table_pass(self):
+        namespace = self._exec_future(dedent("""
+        from __future__ import annotations
+
+        def foo():
+            outer = 1
+            def bar():
+                inner: outer = 1
+            return bar
+        """))
+
+        foo = namespace.pop("foo")
+        self.assertIsNone(foo().__closure__)
+        self.assertEqual(foo.__code__.co_cellvars, ())
+        self.assertEqual(foo().__code__.co_freevars, ())
+
+    def test_annotations_forbidden(self):
+        with self.assertRaises(SyntaxError):
+            self._exec_future("test: (yield)")
+
+        with self.assertRaises(SyntaxError):
+            self._exec_future("test.test: (yield a + b)")
+
+        with self.assertRaises(SyntaxError):
+            self._exec_future("test[something]: (yield from x)")
+
+        with self.assertRaises(SyntaxError):
+            self._exec_future("def func(test: (yield from outside_of_generator)): pass")
+
+        with self.assertRaises(SyntaxError):
+            self._exec_future("def test() -> (await y): pass")
+
+        with self.assertRaises(SyntaxError):
+            self._exec_future("async def test() -> something((a := b)): pass")
+
+        with self.assertRaises(SyntaxError):
+            self._exec_future("test: await some.complicated[0].call(with_args=True or 1 is not 1)")
+
+        with self.assertRaises(SyntaxError):
+            self._exec_future("test: f'{(x := 10):=10}'")
+
+        with self.assertRaises(SyntaxError):
+            self._exec_future(dedent("""\
+            def foo():
+                def bar(arg: (yield)): pass
+            """))
+
+    def test_get_type_hints_on_func_with_variadic_arg(self):
+        # `typing.get_type_hints` might break on a function with a variadic
+        # annotation (e.g. `f(*args: *Ts)`) if `from __future__ import
+        # annotations`, because it could try to evaluate `*Ts` as an expression,
+        # which on its own isn't value syntax.
+        namespace = self._exec_future(dedent("""\
+        class StarredC: pass
+        class C:
+          def __iter__(self):
+            yield StarredC()
+        c = C()
+        def f(*args: *c): pass
+        import typing
+        hints = typing.get_type_hints(f)
+        """))
+
+        hints = namespace.pop('hints')
+        self.assertIsInstance(hints['args'], namespace['StarredC'])
+
+
+if __name__ == "__main__":
+    unittest.main()